Electric water heater



Aug. 14. 1928.

A. J. KERCHER ET AL ELECTRIC WATER HEATER Filed June 28, 1926 K v 3:-1 E 1 FI E Patented ug. 14, 1928.

UNITED STATES .1,680,622 PATENT oEFlcE.

.ARTHUR J'.

KERCHE, OF BERKELEY AND WILLIAM WESLEY HICKS, F SAN FRANCISCO, CALIFORNIA.

ELECTRIC WATER HEATER.

Application filed June 28, 19,26. Serial N0.'118,909.

comprise electrical heating elements whereby hot liquid'may bev stored in the tank to be subsequently withdrawn through faucets or other such devices. It is `common to control ther current sup.

plied to the heating elements Aby means of a' thermostat element` operable to interrupt the' current when the tankfbecomes filled With hot liquid. However, forl household purposes a full tank of hot water is seldom required and Amuch current is wasted by permitting the storage of a full tank before heater in' which the-electrical ,heating ele-Y operation of the device.

causing the current to be interrupted;

It is an object of this invention to devise a thermostatic controll for electrical liquid heaters which may vbe manually adjusted to interrupt the current after the heating of a predetermined quantity of water. It is a further'object of this invention to devise al th'ermostatic element especially .adapted to "be used in combination with a ment is energized upon'ilow of water throug the system. y

Further objects of the invention vwill, ap-

pear from the following" description in which We haye set forth the preferredembodiment.. of our invention. that the' scope of It is to be understood the invention is to be determined from the appended-claims 'and the ystate of the prior art.-

Referring to the drawings: j, 1

Figure 1 is a cross sectional elevational view showing a liquid heater incorporating ,the principles of this invention.

vFig. 2 is ajdetail showing the manual thermostat adjustment. l,

Fig. 3 is a circuit diagram illustrating the Fig. 4 is a cross -sectional .detail taken along the line4-4 Of'Fg. 1. l

The principles of this invention have been incorporated with a liquid heater of the' type shown and described. in ourco-pend plication for electric water heater.

`heater comprises generally an-electric switch for controlling the current supplied to the electrical heating elements, the switch being moved to closed-position in response to How .of liquid through the system and being ins apa Such ay comprising "tablishes communication between caused to moveto open position by a thermostat element.

In this invention the thermost at element has been extended the full height of the storage Itank and is provided with an adjustable connection' to the switch whereby it may be manually controlled to cause' ,the `current to the heating elements to be interrupted after a predetermined l quantity'of water has been heated.

Referring to the drawings, there is shown a conventional type of'liquid storage tank 10 having its lower portion in engagement with an intake pipe 11 which communicates upper portion communicating with an outlet pipe 12 supplying faucets or other such de- Vices. Associated with the tank 10 is an electrical heating element 13 which is preferably placed external of the tank 1() within an auxiliary reservoir 14. The reservoir 14 has its upper and lower portions in communication with the upper and lower portions of the tank 10 respectivelyy through pipes 16and' 17 whereby a thermal circulation may be induced between the tank 10 and reservoir 14.- With such an arrangement when the electrical heating element 13 is energized, heated liquid from the reservoir 14 will be stored inthe upperI portion of the tank 10 while cold liquid from the tank 10 will be drawn into the lower portion of the reservoir 14.

vwith a source of cold liquid, and having its For controlling the' current supplied to A the electric heating element 13 there is provided a switch 19 comprising movable and stationary contacts 20 and 21 respectively which are .connected in series with a source of current and the heating movable contact 2O is provided with suitable insulating mounting upon one end of a lever 22, the lever being' pivotally mounted as at 234 so as to permit movement of the contact 20l into and out of engagement with contact 2,1.

For moving the contact`20 to closed posi` tion therevis lprovided a pressure responsive device 22E-which is inserted between the inbtake pipe'v11' and lthe tank 10. rIhis pressure or flow responsive device is shown as a piston or plunger 24 operating within a cylinder 26. One end ofthe cylinder 26 is inI coinnfmnication with the pipe 11 while a port 27 inthe cylinder wall es- I the cylinder and pipey or passageway 28 which conelement 13. The

-' `nects with the lower `portion of the tank 10. Upon iow, of water through the pipe 11 in response to the opening of faucets con-v nected to the outlet pipe -12 theliquid pressure against the plunger 24 causes'lt to be 'moved backto expose the port '27 and there- -by establish communicationbetaveenthe pipe d*11 and passageway 28 to permit liquid .to

' new dir-@Guyana the' ankam amiable compression spring 29 may be provided for biasing the plunger 24 towards one end of the cylinder.A An auxiliaryv portV 30 may also be provided fori permitting escape of ,liquid entrapped above the .cylinder 26 in rder to permit it to move freely to expose the port'27.

In order to interconnectthe plunger 24 with themovable l'switch contact' 2 0 there is provided aplunger rod 31 which, extends-to the exterior ofthe cylinder 26. The eaternal end 32jofthis. rod is connected to the switch lever 22 by means of a. resilient toggle i resilent' togg e 33j will bias the lcontact 20 to" connection 33 which is connected `toqthe switch'lever and rod 31 as by 'pivotal connections -34 and' 35 respectively. AThe` pivotal conneetions`23, 34 that wh`enlthe plunger24 is in its lowered position corresponding to a condition when no ilowgof-Y liquid is occurrino through the s stem', theconnection 35 will` be below the (lidad-centerv osition with the result that theopen'p'osition. However,A upon low ofliquid the` plunger 24 is actuated-so as to move the pivotal connection 35 above its deadl f 'center position andthus. cause the toggle 33 `prises a metallic tube v37 havin igh temperature coeilcient thelower end of the tube being fixed to the f pipes zsand v38; vof the tube is-'sea-led and connecte -to an of some'l suitable mate itc biasithe contact `20 towards closed posi- In order toycontrol thev opening of the switch 19 so 'that a desired` predetermined quantity of watermay be heated,`there is provided' a .thermostat element 36 which preferably extends Isubstantially the entire height ofthe storage tank 10; The. particular type vofv thermostat element shown comg a relatively The V-inner or up er end ger lever 4 0 which "is pivotally mounted as at en a ed with the outer end of the rod y g g gages a detentj42 whichiis tired with respect and 35 are arranged so,

of expansion,

`tion. Similarly by jknob. any-given quantity. of hot'liquid may .tity of liquid may the immediate needs. `of. theheating element is only initiated b is adapted to be ,39. This trigger lever. en!

resoyeaa to the lever 22 so that upon movement of the lever to close the contacts 20 and 21, the

trigger latches over the detent( For causing the release of the trigger lever and def tent a sait-able adjustable connectlon .such as the cani 43 .is provided between the lower end ofthe rod 39 and lever 40. Inthe construction illustrated the cam 4 3 is provided with a journal connection 44 to theend of the rod 39 and may be rotated by means of' a rod 45 having suitable control means such as a knob 46 fixed to .its outer end. Assum'- ing Athat the mechanism is inclosed by a easing 48 the control rod 45 may pro]e ct through this' casing as shown in Fig. 2 and 'theacasing may be provided with suitable "graduations 49 for indicating the relative i These graduations 'for example may readM in gallons of liquid to be heated beforeope'ration of the thermo-- positlons ofthe cam `43;

stat element to release the switch 19.

. The operation of the device ismade clear diagram of`Fig. and 21 are conby reference tothe circuit 3.` The switch contacts 2O nected in series with the heating elementV 13.

,and a suitable source of current such as'tlle supply lines 1 and 2.- Upon opening a faucet connected with the outlet pipe l2 a flow of wat-er occurs through the intake pi e 11 with the result thatthe plunger 24 is. reed upwardly to permit communication between the .pipe 11 and thetank 10. At the same time the toggle connection 33 is moved i-ny such a position that itbiases the contacts 20 and 31 to closed position and also causes the detent 42 to engage the trigger/40. As the-circuit through the heating element 13 is, now'closed, hot liquid will begin to be stored within the upper end of the tank 10.

Assuming that' the Control knob 46 has been" set for-the storage of say one third of atank voli-water, the thermostat element 36 will not cause disengagement of the trigger 40 with the detent 42 until substantially this quantity 'of watervvhas beenstored within the tank, after which the tri ger is released `to permit the Acontact 20 to e moved to open posiadjusting the control be maintained within the tank so that a quanbe heated consistent with Since the energization' ilow of' water through the system, it 1s bvious thatduring long periods when no water 'is-withdrawn the device will 'cease to operate with a resulting saving in current.

' We claim:

v1. In a hot liquid supply system, a water tank,l a cold water supply pipe-connected t0 said tank whereby the tank is normally filled' -with' water, a hot Water pipe communicating with the upper portion of said tank,` electrical heating means associated wlth the tankand adapted to store het waterv in the upper portion of the tank'bthermal circulationI and means for contro ing supplying of current to the heating means in accordance with the amount of stored heated water in. the tank.

2. In a hot liquid supply system, afwater tank, a cold liquid supply ypipe connected to ythe tank whereby the tank is normally kept filled with water, a hot liquid withdrawal pipe communicating with the upper portion of the pipe, means including an electrical heating element associated with the tank and adapted to store hot liquid in the upper portion of the same by thermal circulation,

anl electrical switch for controlling'current supplied to said element, and an expansible element for controlling said switch, said element being in thermal contact with thel adapted to store hot liquid in the upper portion of the same by thermal circulation,V van electrical switch for controlling vcurrent ksupplied to said element, an expansible element for controllingsaid switchg-.said element being -in thermal contact with liquid within `the tank and extending substantially the height ofthe tank, and an.v adjustable connection between'saidv element and said .switch whereby setting ot said connection will determine the amount` of heated 'water to be stored in the tank.

4, In a hot liquid supply system, .a liquid I storage tankadapted' to be kept filled with liquid, electrical heating means associated with the tank for storing hot liquid within the same, s Witch means for controlling the current supplied to said heatingmeans, a thermostat element extending substantially the full height of the tank and in-close ther# i i mal contact with the liquid within the same,

`heating .'means comprising a ment' extending substantially the full height'- and an adjustable connection between the thermostat element and switch means whereby the device may be set to interrupt the current to the heating means uponstoring any desired predetermined quantity of liquid.

5. In a hot liquid supply system', a liquid storage tank adapted. tobe' kept filled with liquid,v electrical `heating means' associated l I' wlth the tank for storing hot liquid within the same, switch means for controlling the thermostat element extending :substantially the full height of the tank and in close' thermal contact with the liquid within the same, and means 'including a cam `connecting the current supplied to said'heating means,l a

thermostat element and switch means where- -Y by the device maybe set tointer/rupt-fthe i' "i current to the heating means upon'sto a predetermined lquantity of hot liqui,

6. In a hotliquid' supply system,fastorage tank 'adapted to be kept filled with liquid, electrical heating means associatedv withsaid tank, means .responsive-toA` a l'ow offiwater through said system to causecurrent. be supplied to said heating means, and ns. for linterrupting the current supplied to said;

of the tank and in close-thermal Contact with the liquid within the same, switch means in the circuit supplying the heating means, and an adjustable connection' between the thermostat element and switch means.

7. In a hot liquid supply system, a storthermostat ele? n.

age tank adapted to be kept filled with liq'- uid, electrical heating means associated with said tank whereby hot liquid may be stored in the upper portion 'ofl said tank, pressure actuated means responsive to flow of liquid lthrough the 'system to. cause current to be supplied' to said heating means, and man. ually controllable means for automatically interrupting-the supplying of current to the heating means .upon storage of a predetermined quantity of hot liquid in said tank.

In testimony whereof, we have hereunto set our hands.

ARTHUR J. KERCHER 'i A WILLIAM WESLEY Hicks. 

